Advances in pain recognition tools — grimace scales, biomarkers, and AI-assisted assessment — are transforming the ability to detect and treat pain across species.
Pain recognition is the bottleneck of animal welfare: suffering that is not recognised is not treated, and animals cannot report their pain verbally. Grimace scales based on facial action units — eye closure, cheek flattening, whisker position — allow objective assessment of pain states that were previously invisible. AI-assisted assessment reduces the subjectivity and training burden of human observation. The welfare gain from better pain recognition is immediate: earlier, more consistent treatment of conditions that were previously managed inadequately or not at all.